Sunday, January 27, 2013

Some Wobbly Numbers: a response

Via an email received while away on a WEB Dr Gershwin responds to our piece "Some Wobbly Numbers".
Received 8/1/2013. Our comments in (italics).

Thank you for a very entertaining article! I was unaware of the ‘raining jellyfish’ report and will add that to my archives. (No Worries).

I am intrigued and inspired by your interest in this subject, and would like to invite you to be part of my research team in ferreting out obscure historical reports  (We are always on the look out for a beat up-suggest you bookmark this blog for future Jellyfish madness. Of course any use of material generated would be on  a fee for service arrangement. But here's another freebie or three "Dead Jellyfish cause exodus". A simple search of "Jellyfish" at the NLA's excellent Newspaper Archive will find many more, or try the British Newspaper Archive which will yield such gems - for a fee - as "ATTACKED BY A JELLYFISH" and JELLYFISH INVADE FORTH or JELLYFISH INVADE CARNOUSTIE GOLF COURSE).

There seems to be some confusion between the Irukandji stings at Fraser and jellyfish blooms in general. The Fraser stings probably have less to do with general jellyfish bloom dynamics than with cubozoan response to the wonky weather pattern  that we are currently in. Jellyfish blooms in general seem to have more to do with response to various human impacts than with climate per se (although some very well studied blooms correlated with climate). (So wonky weather to blame! Pity that the ABC did not report this. Perhaps you can send a complaint to ABC HQ so they will correct their misleading article. We'd be happy to post your complaint and their reply).

You see, not all species respond in the same ways and degrees to the same stimuli.  (err Der Fred).

The study that you referenced about 'no evidence of increase' is paradoxically of little relevance to the current discussion on jelly blooms. (As your discussion below indicates its actually highly relevant and something the ABC should have sought comment on, instead on relying on just one "expert".)  Instead of examining the obvious question of nuisance jellyfish responses to human impacts, they very broadly and superficially looked at all jellyfish over the whole world. There was so much noise in their data that no pattern was detected. It would be similar to studying the research question “do flowers bloom in the spring” and finding that because some species don’t in some places, therefore a uniform “yes” could not be concluded. Thus the importance of coupling the right sampling with the right question.

However, two studies that immediately followed used a more appropriate methodology and found strong evidence of a relationship between human impacts and jellyfish blooms: (1) Brotz, L. et al. 2012. Increasing jellyfish populations: trends in Large Marine Ecosystems. Hydrobiologia 690: 3-20, and (2) Purcell, J. E. 2012. Jellyfish and ctenophore blooms coincide with human proliferations and environmental perturbations. Ann. Rev. Mar. Sci. 4: 209-235. There have since been numerous other long-term studies published, which also refute Condon's conclusions.

Consider the following:  Brotz analysed jellyfish blooms in 45 so-called Large Marine Ecosystems, and found an increasing trend in 28 (62%), a decreasing trend in 3 (7%), and no obvious trend in 14 (31%). Similarly, Purcell found that 6 of the world's top 10 impacted regions, plus 8 others in the top 100, coincide with regions of notable recent jellyfish blooms and high indicator values. Many of the other highly-impacted ecoregions may well be experiencing jelly?sh bloom problems too, but remain undocumented for whatever reason.

Moreover, there seems to be general confusion over the subtle distinction between trends and problems. It would be ludicrous to suggest that as long as the current rate of cancer stays the same, then that’s ok.  Regardless of how or why people get different types of cancer, and of inclining or declining trends, cancer is a problem and should be researched for better outcomes.  If you had cancer, the announcement that there is insufficient evidence to demonstrate that cancer is on the increase would bring you no relief. Similarly, if you run a business or work in an industry that is heavily impacted by jellyfish, the JEDI announcement is a joke.
(Not entirely sure where this paragraph is going, is it a joke?)

Finally, if you have read the paper in question (Condon, R. H et al. 2012. Questioning the Rise of Gelatinous Zooplankton in the World's Oceans. BioScience 62: 160-169), you will have found that they do actually acknowledge that jellyfish blooms appear to be on the rise in some areas, and that jellyfish do respond to human impacts, but that due to historical lack of research interest in the subject, we lack good long term data to be able to fully understand what contemporary blooms mean.

All well and good, but entirely irrelevant. We merely used the popular literature to demonstrate that there have been jelly fish problems in the past, and there will be in the future. It's a pity no one seems to have done some basic literature review work that would look at the history of jelly fish problems in Australia and elsewhere. And please note there are no jelly fish deniers here! In regard to comments about Condon's work suggest you take it up with Condon; perhaps through a comment to the journal in question. Afterall that's the usual manner of criticism of academic work. Lengthy diatribes sent to an obscure blog are unlikely to meet with much approval on your next ARC grant submission. We note in their press release  Condon state the following which you presumably consider to be of little relevance"Given the potential damage posed by jellyfish blooms to fisheries, tourism and other human industries, the findings of the group foretell recurrent phases of rise and fall in jellyfish populations that society should be prepared to face."

I have a popular science book coming out in May on this very subject ( ) (One hopes any profits generated will be put to good use, I know of some important cancer research that is looking for support) . If you really believe that jellyfish blooms are bunk (I don't! My point clearly made is that they have occurred before and are likely to occur again. Seems like someone wasn't paying attention.) , it might be best if you don’t read it – it would just make you angry (think you have the wrong person there. Jelly fish numbers are not something that gets my goat. ABC's continued abuse of its charter on the other hand does turn my stomach). On the other hand, if you are interested to learn about something that has probably been off your radar until now, you might find it quite interesting. (Perhaps you can send me a free copy, I'd me happy to provide a review).

Sincerely, Dr Lisa-ann Gershwin

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